My girlfriend's VW Polo has water inside, behind the dashboard. A few days ago water started pouring over her feet while she was driving. Fuck, you could even hear it splashing when the car turned. I don't know how it got there, but looking under the hood I see a weird looking plastic in a hole. I pull, and this is what I get:

Do you think that is a stock part? Doesn't look very... professional. I don't even know if that hole leads inside the cabin, but if it does (it looks so), what the fuck was VW thinking putting a fucking funnel there?

If the car has air-conditioning then it's probably caused by a clogged condensate drain.
Gerard._________________To install Gentoo I use sysrescuecd.Based on Gentoo,has firefox to browse Gentoo docs and mc to browse (and edit) files.
The same disk can be used for 32 and 64 bit installs.
You can follow the Handbook verbatim.
http://www.sysresccd.org/Download

The Polo was built primarily in Spain from the mid '80s until 2002. In 2002, VW finally remembered that the Spanish are fucking lazy and had Mexicans build them instead.

Seriously though, what you're looking for is a firewall grommet. I did some a quick google for "vw polo firewall grommet part number" but didn't come up with any directly applicable -- lots of Golf stuff, which is fairly similar but there's a lot of differences. A lot of other car stereo idiots talking about just removing the grommet to feed heavier gauge wire through to whatever. AFAIK no Polo derivative is sold in the US, so that sort of limits the English speaking exposure. I'd recommend asking on an actual VW forum, preferably a Spanish one._________________My political bias.

A chunk of heavy foam rubber with a slit cut into it ought to serve just fine. No need to spend $50 on a part like that for an old beater._________________History teaches us that men and nations behave wisely once they have exhausted all other alternatives. -- Abba Eban

In the end I took it to the mechanic. It also has some starting problems, probably some b0rked engine heaters (god, I hate diesels), so two birds with one stone. He said whoever put that thing there didn't know what they were doing, since that hole is harmless . The problem is probably a clogged windshield drain. He'll call tomorrow.